#include<iostream>
#include<cstdlib>
#include<stdio.h>
#include<vector>
using namespace std;
vector<int>v[110];
int dfs(int x,int pre)
{
    int ans=0;
    for(int i=0;i<v[x].size();i++)
    {
        if(v[x][i]!=pre)
        ans^=(1+dfs(v[x][i],x));
    }
    return ans;
}
int main()
{
    int n,m,a,b;
    while(scanf("%d",&n)!=EOF)
    {
        int ans=0,cnt=0;
        while(n--)
        {
            scanf("%d",&m);
            for(int i=1;i<=m;i++)
            v[i].clear();
            for(int i=1;i<m;i++)
            {
                scanf("%d%d",&a,&b);
                v[a].push_back(b);
                v[b].push_back(a);
            }
            int s=dfs(1,-1);
            if(s>1) cnt++;
            ans^=s;
        }
        if(cnt>=1)
        {
            if(ans) puts("PP");
            else puts("QQ");
        }
        else
        {
            if(ans) puts("QQ");
            else puts("PP");
        }
    }
}

PP and QQ

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 209    Accepted Submission(s): 81

PP and QQ were playing games at Christmas Eve. They drew some Christmas trees on a paper:

Then they took turns to cut a branch of a tree, and removed the part of the tree which had already not connected with the root. A step shows as follows:

PP always moved first.
PP and QQ took turns (PP was always the first person to move), to cut an edge in the graph, and removed the part of the tree that no longer connected to the root. The person who cannot make a move won the game.

Your job is to decide who will finally win the game if both of them use the best strategy.

2
2
1 2
2
1 2
1
2
1 2

PP
QQ